Load-sensing cartridge counter

ABSTRACT

A load-sensing base, cartridge and method are provided for use with a firearm. The cartridge includes a support element that moves a cartridge into a chamber of the firearm. The base includes a load sensor that senses a load applied by the support element and outputs a load sensing signal. The bases also include a cartridge counter, coupled to the load sensor, that uses the load sensing signal to determine a number of cartridges remaining.

FIELD OF INTEREST

The present inventive concepts relate to the field of firearms, and moreparticularly to magazines used in firearms.

BACKGROUND

Typical firearms offer no mechanism to communicate to the user a numberof cartridges in a magazine of a firearm. For various reasons, thiscould be extremely useful information for the user.

Various approaches for determining the number of cartridges remaining ina magazine have been suggested. For example, U.S. Patent Publication20080276517 entitled Cartridge Counter describes two types of magazinesthat determine the number of cartridges in a magazine, each uses adistance detector. These magazines are described with respect to FIGS.1-3 provided herein, which also appear in U.S. Patent Publication20080276517.

In prior art FIGS. 1 and 2, a magazine 29 is shown that can be insertedinto a firearm, such as handgun 11 shown in FIG. 3. The firearm 11includes a handle or grip 12 within which magazine 29 is inserted toload the firearm. The magazine includes cartridges (e.g., bullets,rounds) 21 that are deposited within a chamber of the firearm from themagazine.

Magazine 29 includes a hollow cross section polygonal frame or shell 27,substantially rectangular, suitable for the dimensions of the cartridges21 that will be stored in the magazine 29.

The near end of the magazine 29 is fitted into firearm 11, whichincludes an entry/exit hole for cartridges 21 of magazine 29 (or accessaperture); i.e., a fitting hole located in the upper part of themagazine 29 when it is supported at the opposite end in a substantiallyvertical position.

The other end, opposite to the magazine 29 access hole, is closed by asurface or base 28 of the magazine 29 that serves as a seating orsupport to a first push spring 24 of the magazine 29, and moves anammunition push means 22, such as a tile, longitudinally between theempty magazine 29 position where the spring is unstressed and fullmagazine 29 where the first spring 24 is compressed.

Consequently, the cartridges 21 stored in the magazine 29 are movedtoward the magazine 29 entry each time a cartridge 21 is expelled out ofthe magazine 29, or towards the base 28 each time a cartridge 21 isadded through the magazine 29 access hole.

As a result of the push effort made by the first spring 24, the tile 22moves upward or downward depending on if a cartridge 21 is extracted orintroduced into the magazine 29.

A distance detection means (or perceiver) 25 measures the distancebetween the tile 22 and the base 28. The distance perceiver 25 islocated in a place configured for such purpose between the tile 22 andthe base 28 of the magazine 29. Thus, when the tile 22 moveslongitudinally, the distance perceiver 25 generates an electric signalthat indicates the longitudinal movement made by the tile 22, eitherupward toward to the access hole or downward toward the base 28.

The distance perceiver 25 includes a first set of electric terminals 26adapted to make electric contact with a second set of electric terminals41 located at the tip of the firearm 11. Obviously, both sets ofterminals 26, 41 face each other when the magazine 29 is loaded into thefirearm 11.

The first set 26 of electric terminals can be placed, for example, atthe entrance of the magazine 29 fitting location in the case of apartially fitted magazine (e.g., sub rifle, assault rifle, lightweightmachine gun, etc.), or in the other end of the magazine casing 27 whentotally fitted inside the handle of a firearm 11, such as the pistoldisplayed in FIG. 3.

A microprocessor (not shown) is located in a location provided for suchpurposes in the firearm 11 handle 12. When the magazine 29 is fittedinto the firearm 11, both first and second electrical terminals 26,41are in electrical contact and allow an electric signal, relative to themovement of the push tile 22, to be sent from the distance perceiver 25through both sets of contacts and electric connections to themicroprocessor, which are also connected via electrical connections to adisplay 13, located in the body or casing of the firearm and in sight ofthe shooter when pointing the firearm 11 to a potential target.

In FIG. 1, the distance perceiver 25 is connected to the tile 22 througha second spring 23, so that its near end is connected to the distanceperceiver 25 and the other end is connected to the lower part of thepush tile 22. The distance perceiver 25 receives from the second spring23 a signal that is the result of extending the second 23 spring. Thesignal received varies between a value that corresponds with the maximumnumber of cartridges 21 that can be stored in a magazine 29 and a valuethat corresponds to the minimum number of cartridges 21 stored in themagazine 29. The signal received by the distance perceiver 25 isconverted into an electric signal that is sent to the microprocessor,which transforms it into a count visible on the display 13 shown in FIG.3.

In FIG. 2, the perceiver 25 determines distance using an infrared beam,i.e., the variation of tile 22 position is calculated using an infraredlight emitting diode 33 that emits an infrared signal reflected by theunderside of the tile 22, and received by a receiving diode 34. Bothdiodes 33, 34 are connected to the distance perceiver 25. Consequently,the signal received by the distance perceiver 25 from the receivingdiode 34 is the result of the distance between tile 22 and the magazine29 base 28. The signal received varies between a value that correspondswith the maximum number of cartridges 21 that can be stored in themagazine 29 and a value that corresponds with the minimum number ofcartridges 21 stored in the magazine 29.

In FIG. 2, the tile 22 includes a reflecting surface on its underside,suitable to reflect an infrared light beam. Both the projected andreflected beam travel through an empty space between the spirals of thefirst 24 spring with no elements external to the system interfering intheir course. The distance perceiver 25 transforms the signal receivedinto an electric signal that is sent to the microprocessor, which turnsit into a count visible on the display 13 shown in FIG. 3.

In the above embodiments, the design of the firearm must be altered toadd the display 13. Requiring such alteration adds to the cost of thefirearm. Retrofitting existing firearms with such a display could bedifficult, as well as costly, if not impossible.

Also in the above embodiments, several components of the magazine mustbe redesigned or new components added. Retrofitting existing magazines,if possible, would be extensive and costly. It likely that existingmagazines would be discarded and completely new magazines required. Suchnew magazines would have distance measuring and counter partsdistributed throughout. Failure of any such parts could cause thecounter to fail. Since the parts are distributed throughout themagazine, it is likely the entire magazine would have to be replaced.Reliability can be low in such prior art magazines, as debris can beeasily introduced into the magazine and cause failure of mechanical oroptical components.

SUMMARY

In accordance with various aspects of the present invention, aload-sensing cartridge counter is provided that does not requirealteration or redesign of the firearm. The load sensing cartridgecounter is implemented within a magazine base, in a simple design. As aresult, if the counter fails, preferably only the base needs replacing.In preferred embodiments, the base fits on existing magazines, so usersdo not have to discard existing magazines in favor of completely newload-sensing magazines or firearms.

In accordance with one aspect of the present invention, provided is aload-sensing magazine for use with a firearm. The load sensing magazineincludes a shell configured to hold a plurality of cartridges, a firstend of the shell configured to couple to the firearm; a push tile withinthe shell and configured to receive a cartridge from the plurality ofcartridges; a biasing element that biases the push tile toward the shellfirst end to load the cartridge into a chamber of the firearm; a baseenclosing a second end of the shell, the base comprising a load sensorthat senses a load applied by the biasing element and outputs a loadsensing signal; and a cartridge counter, coupled to the load sensor,that uses the load sensing signal to determine a number of cartridges inthe magazine.

The load-sensing magazine can further include an output device thatoutputs an indication of the number of cartridges.

The load sensor can be a strain-gauge load cell.

In accordance with another aspect of the invention, provided is aload-sensing base for use with a firearm magazine that includes asupport element that moves a push tile toward a shell first end to loada cartridge into a chamber of the firearm. The base includes a loadsensor that senses a load applied by the support element and outputs aload sensing signal, and also includes a cartridge counter, coupled tothe load sensor, that uses the load sensing signal to determine a numberof cartridges remaining.

The base can further include an output device that outputs an indicationof the number of cartridges remaining.

The output device can include a display that displays the number ofcartridges.

The display can be a digital number display.

The brightness and wavelength of illumination of the display can bealtered to suit ambient lighting and users requirements.

The variation of display illumination can be made to occurautomatically, or in response to user input.

The output device can include an audio device that outputs theindication of the number of cartridges as an audio output.

The audio device can output the audio output as a number correspondingto the number of cartridges.

The output device can include an actuator that selectively enables ordisables the audio output.

The output device can be configured to output the indication of thenumber of cartridges or other signal when the number of cartridges inthe firearm or magazine is at or below a threshold number.

A tactile transducer, such as a vibrating device can be included toalert the user silently that the number of cartridges in the firearm ormagazine is at or below a threshold number.

The number of cartridges can include one or more cartridges in thechamber and cartridges in the magazine.

The cartridge counter can be configured to count a number of cartridgesfired from the firearm.

The cartridge counter can use a predetermined load-to-cartridgerelationship to determine the number of cartridges.

The cartridge counter can use a combination of a count of cartridgesloaded and/or fired and a predetermined load-to-cartridge relationshipto determine the number of cartridges.

In accordance with another aspect of the present invention, provided isa method of determining a number of cartridges in a firearm. The methodincludes sensing a load applied by an element supporting cartridgeswithin a magazine; generating a load sensing signal in response to thesensed load; determining a number of cartridges remaining from the loadsensing signal; and outputting an indication of the number ofcartridges.

A predetermined load-to-cartridge relationship can be used to determinethe number of cartridges.

A combination of a predetermined load-to-cartridge relationship and acount of cartridges loaded and/or fired can be used to determine thenumber of cartridges.

The method can further include outputting the indication via an outputdevice.

Outputting the indication can include generating a display representingthe indication.

Outputting the indication can include generating an audio outputrepresenting the indication.

The method can further include selectively enabling and disabling theoutputting.

The method can include providing the output or other signal when thenumber of cartridges in the magazine is at or below a threshold number.

The signal provided when the number of cartridges in the magazine is ator below a threshold number may be a silent tactile signal, such as avibration.

Determining the number of cartridges remaining can include determiningone or more cartridges in the chamber and cartridges in the magazine.

The method can further include determining a number of cartridges fired.

The method can include a calibration sequence performed during loading,unloading, or firing of the firearm, at a time chosen automatically, orin response to specific user input.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more apparent in view of the attacheddrawings and accompanying detailed description. The embodiments depictedtherein are provided by way of example, not by way of limitation,wherein like reference numerals refer to the same or similar elements.The drawings are not necessarily to scale, emphasis instead being placedupon illustrating aspects of the invention. In the drawings:

FIG. 1 shows a section perspective view of a prior art magazine fromU.S. Pat. Pub. 20080276517;

FIG. 2 shows a section perspective view of another prior art magazinefrom U.S. Pat. Pub. 20080276517,

FIG. 3 is a perspective view of a prior art handgun, as an example of afirearm specially designed to use the magazines of FIGS. 1 and 2;

FIG. 4 is a perspective view of an embodiment of magazine in accordancewith aspects of the present invention; and

FIG. 5 is a perspective view of a handgun, as an example of a firearm,with which the magazine of FIG. 4 can used.

FIG. 6 is a block diagram of the functional elements of an embodiment ofthe base (50) of FIG. 4.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Hereinafter, aspects of the present invention will be described byexplaining illustrative embodiments in accordance therewith, withreference to the attached drawings. While describing these embodiments,detailed descriptions of well-known items, functions, or configurationsare typically omitted for conciseness.

It will be understood that, although the terms first, second, etc. arebe used herein to describe various elements, these elements should notbe limited by these terms. These terms are used to distinguish oneelement from another, but not to imply a required sequence of elements.For example, a first element can be termed a second element, and,similarly, a second element can be termed a first element, withoutdeparting from the scope of the present invention. As used herein, theterm “and/or” includes any and all combinations of one or more of theassociated listed items.

It will be understood that when an element is referred to as being “on”or “connected” or “coupled” to another element, it can be directly on orconnected or coupled to the other element or intervening elements can bepresent. In contrast, when an element is referred to as being “directlyon” or “directly connected” or “directly coupled” to another element,there are no intervening elements present. Other words used to describethe relationship between elements should be interpreted in a likefashion (e.g., “between” versus “directly between,” “adjacent” versus“directly adjacent,” etc.).

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes” and/or “including,” when used herein, specifythe presence of stated features, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, steps, operations, elements, components, and/or groupsthereof.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like may be used to describe an element and/or feature'srelationship to another element(s) and/or feature(s) as, for example,illustrated in the figures. It will be understood that the spatiallyrelative terms are intended to encompass different orientations of thedevice in use and/or operation in addition to the orientation depictedin the figures. For example, if the device in the figures is turnedover, elements described as “below” and/or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.The device may be otherwise oriented (e.g., rotated 90 degrees or atother orientations) and the spatially relative descriptors used hereininterpreted accordingly.

FIG. 4 shows an embodiment of a magazine 100 in accordance with aspectsof the present invention. Like magazine 29 of FIGS. 1 and 2, magazine100 is configured to hold cartridges 21 that are pushed upward away froma base by a spring 24 and push tile 22. A shell 27 encases thecartridges 21, spring 24, and push tile 22—which are all part of aconventional magazine.

However, unlike conventional magazines, magazine 100 includes a base 50that has a load sensor 52. The load sensor can be, as an example, astrain gauge load cell. In other embodiments, the load sensor can be orinclude a piezoelectric load sensor. Load sensor 52 is disposed withinthe base 50 to have a bottom end of the spring 24, opposite the pushtile 22, apply a force thereto. The amount of force exerted on loadsensor 52 is related to the number of cartridges 21 in the magazine 100.The more cartridges 21 in magazine 100, the greater the force exerted byspring 24 on load sensor 52.

A cartridge counter 54 is also included in base 50. The cartridgecounter 54, which includes a processor or microprocessor 60 and memory61, is configured to receive a load sensing signal from load sensor 52and to translate that signal into a number of cartridges 21 remaining inthe magazine 29. Translating the load sensing signal into a number ofcartridges can include using a predetermined load-to-cartridgerelationship stored in the memory of the cartridge counter. Therelationship can be the same for magazines of the same type, anddifferent for magazines of different types.

Suitable circuitry, according to known principles, may be used to couplethe load sensor 52 to the processor 60. This may include anamplifier/signal conditioner 57, and an analog to digital converter 58.

The processor 60 may use known principles to improve the accuracy of thetranslation of sensed load into cartridge count. For example, theprocessor 60 may be programmed to average a succession of counts, toimplement digital filtering of the sensed data, or to employ stochasticor “fuzzy logic” principles.

The loading or firing of a cartridge may also be detected by a change ofthe signal from the load sensor 52. The processor 60 may also use thisinformation in determining the the cartridge count.

As the mechanical force exerted by the spring 24 may be altered by largevariations in temperature, a temperature sensor 65 can be included tointroduce a compensation factor into the determination of the cartridgecount.

The cartridge counter 54 can also be configured to keep a history ofshots fired, which may or may not include a time and a date of thefiring of each cartridge. Cartridge counter 54 can keep this history formagazines on an individual basis, for the gun across multiple magazines,or both.

The base 50 can output the number of cartridges, or other data orinformation that cartridge counter 54 stores or generates, to a memory,a graphical display, an audio output, a wireless transmitter, a dataport, or some combination thereof. One or more of these output types canbe represented by output device 56.

The output device 56 can be or include a display 62, for example, an LCDdisplay or LED display. The output device 56 can be or include an audiodevice, for example, a speaker. As a data port, the output device couldinclude a USB port or Firewire, as examples. As a wireless transmitter,the output device could include a radio frequency (RF) transmitter,Wi-Fi transmitter (e.g., Bluetooth), cellular transmitter, or otherwireless transmitter.

The output device 56 can include a sensor 64 to determine the level ofambient lighting, so that the processor 60 can adjust the illuminationlevel of the display 62 to a suitable level. The sensor 64 can, forexample, be a phototransistor or light-dependant-resistor. Thebrightness may be adjusted continuously, or in discrete steps. Userinput from the user input actuator 59 may also be used in determining oradjusting the brightness level.

The illumination device 66 of the display 62 can be made to selectivelyprovide a choice of colors or wavelengths of light. This may be doneaccording to well-known principles by selectively illuminating LED lightsources used to illuminate the display. For example, a first LED 67 mayilluminate the display at 600 nm for use by the unaided eye. A secondLED 68 may illuminate the display at 800 nm for use with night-visionequipment. The selection of wavelength may be made through the userinput actuator 59.

As an example, a numeric display can output a number indicating thenumber or cartridges remaining in the firearm or magazine. Also as anexample, an audio output can output a number indicating the number ofcartridges remaining in the firearm or magazine. If the output device 56includes a display or audio output, in various embodiments the base caninclude an actuator 59 that selectively enables or disables the displayoutput, audio output, or both—such as a switch or button. In someembodiments, the actuator can be, for example, a button that causesoutput of the number of cartridges remaining when it is pressed. Such abutton could also be used to calibrate the cartridge counter, e.g., whenthe magazine is refilled with cartridges, or to select user options suchas display brightness or threshold counts.

The output device can be configured to output the number of cartridgesor other signal via display, audio output, or both when the number ofcartridges in the firearm or magazine is at or below a threshold number,e.g., 25% of the cartridges remain. For example, the display could flashwhen the number of remaining cartridges is at or below the threshold. Asanother example, a low tone can be output from an audio output when thenumber of remaining cartridges is at or below the threshold. In someembodiments, there can be multiple thresholds, and there can be adifferent graphical, audio, or both output for each threshold. Forexample, there could also be a threshold for the situation where thereis one cartridge remaining.

The output device 56 may also include a tactile transducer 63, such as asmall motor with an eccentric weight, which can silently produce avibration or other tactile sensation to alert the user when theremaining cartridge threshold is reached.

In order to conserve battery power, the cartridge counter 54 can beconfigured to turn off the output device 56, and to employ other wellknown power-saving measures, such as processor “sleeping,” when themagazine is idle (not in the process of being loaded or fired). Thecartridge counter 54 may furthermore be configured to restore power tothe display and return to normal operation on a sudden change of readingfrom the load sensor 52, such as from loading a cartridge 21,discharging the firearm, or striking the base 50 with the hand. Thecartridge counter may also be configured to restore power throughdetection of biometric information, such as reading a thumb print of anauthorized user, e.g., using a known thumb print reader.

The output device 56 may be configured to display some indication otherthan “0” when the magazine is empty, so that the user will not bedeceived into thinking the firearm itself is empty when a cartridge 21may still be present in the firing chamber. The indication “Ch”, for“Chamber” may be shown, for example.

While the foregoing has described what are considered to be the bestmode and/or other preferred embodiments, it is understood that variousmodifications can be made therein and that the invention or inventionsmay be implemented in various forms and embodiments, and that they maybe applied in numerous applications, only some of which have beendescribed herein. It is intended by the following claims to claim thatwhich is literally described and all equivalents thereto, including allmodifications and variations that fall within the scope of each claim.

1. A load-sensing magazine for use with a firearm, comprising: a shellconfigured to hold a plurality of cartridges, a first end of the shellconfigured to couple to the firearm; a push tile within the shell andconfigured to receive a cartridge from the plurality of cartridges; abiasing element that biases the push tile toward the shell first end toload the cartridge into a chamber of the firearm; a base enclosing asecond end of the shell, the base comprising a load sensor that senses aload applied by the biasing element and outputs a load sensing signal;and a cartridge counter, coupled to the load sensor, that uses the loadsensing signal to determine a number of cartridges in the magazine. 2.The load-sensing magazine of claim 1, further comprising: an outputdevice that outputs an indication of the number of cartridges.
 3. Theload-sensing magazine of claim 2, wherein the output device isconfigured to alter the brightness and wavelength of illumination of thedisplay.
 4. The load-sensing magazine of claim 3, wherein the outputdevice is configured to automatically alter the brightness andwavelength of illumination of the display.
 5. The load-sensing magazineof claim 3, wherein the output device is configured to alter thebrightness and wavelength of illumination of the display in response toa user input.
 6. The load-sensing magazine of claim 1, wherein theoutput device includes: a tactile transducer that causes a vibration toalert the user silently that the number of cartridges is at or below athreshold number.
 7. The load-sensing magazine of claim 1, wherein theload sensor is a strain-gauge load cell.
 8. A load-sensing base for usewith a firearm magazine that includes a support element that moves apush tile toward a shell first end to load a cartridge into a chamber ofthe firearm, the base comprising: a load sensor that senses a loadapplied by the support element and outputs a load sensing signal; and acartridge counter, coupled to the load sensor, that uses the loadsensing signal to determine a number of cartridges remaining.
 9. Thebase of claim 8, further comprising: an output device that outputs anindication of the number of cartridges remaining.
 10. The base of claim9, wherein the output device includes a display that displays the numberof cartridges.
 11. The base of claim 10, wherein the display is adigital number display.
 12. The base of claim 9, wherein the outputdevice includes an audio device that outputs the indication of thenumber of cartridges as an audio output.
 13. The base of claim 12,wherein the audio device outputs the audio output as a numbercorresponding to the number of cartridges.
 14. The base of claim 9,wherein the output device includes an actuator that selectively enablesor disables the audio output.
 15. The base of claim 9, wherein theoutput device is configured to output the indication of the number ofcartridges or other signal when the number of cartridges in the firearmor magazine is at or below a threshold number.
 16. The base of claim 15,wherein the output device includes: a tactile transducer that causes avibration to alert the user silently that the number of cartridges is ator below the threshold number.
 17. The base of claim 9, wherein theoutput device is configured to alter the brightness and wavelength ofillumination of the display.
 18. The base of claim 17, wherein theoutput device is configured to automatically alter the brightness andwavelength of illumination of the display.
 19. The base of claim 17,wherein the output device is configured to alter the brightness andwavelength of illumination of the display in response to a user input.20. The base of claim 8, wherein the load sensor is a strain-gauge loadcell.
 21. The base of claim 8, wherein the number of cartridges includesone or more cartridges in the chamber and cartridges in the magazine.22. The base of claim 8, wherein the cartridge counter is configured tocount a number of cartridges fired from the firearm.
 23. The base ofclaim 8, wherein the cartridge counter uses a predeterminedload-to-cartridge relationship to determine the number of cartridges.24. A method of determining a number of cartridges in a firearm,comprising: sensing a load applied by an element supporting cartridgeswithin a magazine; generating a load sensing signal in response to thesensed load; determining a number of cartridges remaining from the loadsensing signal; and outputting an indication of the number ofcartridges.
 25. The method of claim 24, wherein a predeterminedload-to-cartridge relationship is used to determine the number ofcartridges.
 26. The method of claim 24, further comprising: outputtingthe indication via an output device.
 27. The method of claim 26, whereinoutputting the indication includes generating a display representing theindication.
 28. The method of claim 27, wherein the display includes anumber of cartridges.
 29. The method of claim 26, wherein the displaybrightness is variable.
 30. The method of claim 26, wherein outputtingthe indication includes causing a vibration of the firearm.
 31. Themethod of claim 26, wherein outputting the indication includesgenerating an audio output representing the indication.
 32. The methodof claim 26, wherein the method includes providing the output or othersignal when the number of cartridges in the shell is at or below athreshold number.
 33. The method of claim 24, wherein determining thenumber of cartridges remaining includes determining one or morecartridges in the chamber and cartridges in the magazine.
 34. The methodof claim 24, further comprising: determining a number of cartridgesfired.